COMPARATIVE-STUDY OF ORAL AND WRITTEN PICTURE DESCRIPTION IN PATIENTSWITH ALZHEIMERS-DISEASE

Oral and written picture descriptions were compared in 22 patients wit h Alzheimer's disease (AD) and 24 healthy elderly subjects. AD patient s had a significant reduction of all word categories, which, similarly to controls, was more pronounced in written than in oral texts. They also reported fewer information units than controls, but without task difference. At the syntactic level, written descriptions of AD subject s were characterized by a diminution of subordinate clauses and a redu ction of functors. More grammatical errors were present in written des criptions by AD and control subjects. AD and control groups produced a n equivalent number of semantic errors in both tasks. However, in oral description, AD patients had more word-finding difficulties. In sum, AD descriptions were always shorter and less informative than control texts. Additionally, written descriptions of AD patients appeared shor ter and more syntactically simplified than, but as informative as, ora l descriptions. Whereas no phonemic paraphasias were observed in eithe r group, AD patients produced many more graphemic paragraphias than co ntrols produced. Furthermore, written descriptions had more irrelevant semantic intrusions. Thus, as compared to oral descriptions, written texts appeared to be a more reliable test of semantic and linguistics difficulties in AD. (C) 1996 Academic Press, Inc.